1. Field of the Invention
The present invention relates to a control device of an internal combustion engine that monitors an operating state of a microcomputer controlling at least a fuel injection device and that activates a fuel cut failsafe function when an abnormality in the microcomputer is detected.
2. Description of Related Art
A control device of this kind for an internal combustion engine is described in Patent document 1 (PCT application Japanese translation No. H4-500846), for example. The control device compulsorily activates a fuel cut failsafe function when deceleration fuel cut (i.e., fuel cut during deceleration) is performed during running of a vehicle and monitors an operation state of the fuel cut failsafe function. Thus, the control device aims to perform abnormality diagnosis of the fuel cut failsafe function without affecting drivability during the running of the vehicle.
However, since the control device described in above Patent document 1 performs the abnormality diagnosis of the fuel cut failsafe function during the deceleration fuel cut period in the running of the vehicle, the vehicle runs in a state where the abnormality diagnosis of the fuel cut failsafe function is not performed during a period since the running of the vehicle is started until the deceleration fuel cut is performed. Therefore, the vehicle running is performed without detecting the abnormality even if the fuel cut failsafe function is abnormal during the period since the running of the vehicle is started until the deceleration fuel cut is performed.